Tenax Therapeutics shares rise 12.38% after-hours as positive LEVEL trial sample size reassessment confirms enrollment on track.

Tenax Therapeutics surged 12.38% in after-hours trading following the announcement of favorable results from the prespecified Blinded Sample Size Re-estimation (BSSR) of its LEVEL Phase 3 trial for TNX-103. The BSSR confirmed the trial is powered at over 90% to detect the primary endpoint (a 25-meter change in 6-minute walk distance) without requiring an increased sample size, maintaining the original enrollment timeline to complete by mid-2026. The company also initiated the global Phase 3 LEVEL-2 study and announced plans for a long-term open-label extension study. CEO Chris Giordano emphasized the validation of key assumptions from prior trials and confidence in the development plan, reinforcing progress toward regulatory milestones. The positive data derisked the program, aligning with the stock’s sharp after-hours rally as investors reacted to reduced trial uncertainty and advancing clinical timelines.